Molded strainer or screen for wells, filters, and the like.



J. R. FREEMAN. R OR SCREEN FOR WELLS, FILTERS, AND THE LIKE.

momma STBAINE APPLICATION FILED JUNE 29,1908.

Patented Dec. 22, 1908.

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' UNITED STATES PATENT OFFICE.

JOHN R. FREEMAN, OF PROVIDENCE, RHODE ISLANIi.

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semen of Letters Patent.

Patented Dec. 22, 1908.

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. To all whom it may concern:

cumstances,

1 most convenient to form it parts:

work of suitable shape and size.

Be it known that I, R. FREEMAN, a citizen of the United States, and resident of Providence, county of Providence, State of Rhode Island, have invented an Improvement in. Molded Strainers Wells, Filters, and the Like, of which the folde emption, in connection with the ecopanying drawing, is a specification, like letters on the" drawing This invention has for its object the production of a. novel-and eflicient strainer or screen which may serve as a lining or casing for wells, filters and the like, and particu? larly adapted for use in lining wells for deriving water from saturated gravel or other earth, or as a base course for filtering material.

As will appear hereinafter the construe tion of the strainer or screen is such that a large proportion thereof presents pore-space for filtration purposes;

The strainer or screen maybe made in cylindrical or in slab form, according to errand is composed of a maximum granular body, such as gravel of assorted sizes, minimum or other suitable cementitious material. The pro ortion of the binder is such that it is just su cient to hold the contacting articles of the body closely together an strength of adhesion ing' a very through which the water filters.

The properly mixed body and binder is molded while moist into the desired sha e, and when hard is inserted in the well or ot er excavation to be lined. In some instances I find it desirable to stren then the strainer or screen by ribs or portions of substantially to the mass, while leavpure cement or concrete, and these strengthening portions may be themselves reinforced by the introduction of metal or other frame- The cylinder or slab is thereby so strengthened as a whole thatit may be more rea il handled without breakage, or forced into p ace.

In using my strainer or screen as a lining for driven or other wells it will probably be in cylindrical sections of suitable diameter and of convenient len h, the sections being inserted into the we opening and superimposed one upon a other.

or Screens for representing like made to adhere by mixture with a binder, such as Portland cement give:

large proportion of pore-space I The various novel features of my invention will be fully described in the subjoined specification and particularly pointed out in the following claims.

Fi re 1 is a; ers ective view of a cylindrica section 0 mo ded strainer or screen embodying my invention, showing the use of strengthening portions; Fig. 2 is a cross-sec tion on the ine 22, Fig. 1, and I have shown metallic reinforcing means in the strengthening portions of the material; Fig. 3 is a perspective view of a curved slab of the molded strainer or screen, strengthened and reinforced; Fig. 4 is an enlarged detail showing the bond or contact formed by the binder between adjacent particles of the body; Fig. 5 is an enlarged sectional view of two part1- cles of the body, illustrating the action of ca illary attraction upon the binder while in fluid form.

In carrying out my invention I take for such as gravel, using such sizes as may be best suited to the particular case, say from 5 inch to 1; inch, and the sizes may and preferably' will be mixed together, and with this body portionI use a binder of cementitious material, such as Portland cement. The binder is of a minimum roportion compared to the body, 'ust enoug being used to hold closely to other the contacting portions of the partic es of the body without filling the interstices, sothat a large pore-space is pre-' sented. 7 The roperly moistened mixture of body and bin er is then molded to the desired shape, which may be cylindrical, or curved or flat slabs, according to the requirements of theicase. In some instances the molded strainer or screen so made will not require additional strengthenin but in other instances it maybe advisa le to provide strengthening means.

Referrin to Flg. 1 I have shown a cylindrical section of the molded material embody' my invention, a skeleton comprising longitu inal portions 1 and circular end portions 2 being made of substantially firfiire concrete, the intervening spaces bein ed w1th the maximum granu ar bod an minimum binder, as indicated at 3. y so constructing thesection it can be readily handled without danger of breakage and can be more easily introduced into position. Where greater strength is required, as when the sections are to e positioned with the exercise of some force or where used in form of slabs the body portion suitable granular material,

required to sustain a heavy weight, I it desirable to reinforce the skeleton with metal. For instance, as shown in Fig. 2, I have illustrated I-bars 4 in two of the longi tudinal strengthening ribs; and in the other two I have shown corrugated metal strips 5, the reinforce being preferably made of steel.

In the curved or segmental slab shown in Fig. 3 the longitudinal strengthening ortions 6 are reinforced by I-bars, as 7, see otted lines, and curved rods 8 may be used to reinforce the u per and lower concrete portions 9 of the slab.

From the foregoing description of my invention it will be manifest that the minimum of binder enables me to provide a maximum pore-s ace for the passage of the water through the strainer or screen, or for the support of still finer filtering material, insuring l a very complete and efficient straining, while the material or porous slab as a whole serves I to hold back the saturated gravel or other soil through which the water is derived. I

In Fig. 4 I have illustrated the relatively large area of bond or contact to give strength of adhesion to the mass, the heavy or thickened lines at 10 indicating the small area of the cementitious binder at the oint of contact between two of the partic cs 11 constituting the body.

The binder in practice is applied in theform of a very thm liquid grout of pure cementand water, and under the laws of capili lary attraction it naturally collects at the points of contact while still in the fluid form, as illustrated on a large scale in Fig. 5, thereby giving adhesion, between contacting particles, over an area much larger than that of the mere contacting point of suchparticles.

As shown in Fig. 5 the capillary action tends to draw the binder while fluid into the crevice and away from such portions of the surfaces of the particles as are not in contact.

My invention is not restricted to any particular form forthe lining sections, nor'to any particular character of material for the body, nor to the size of the particles thereof, so long as the same, when united by the binder, will present a large pore-s ace. Nor is it restricted to a porous durab e material to be used for the special purpose herein detwo subscribing witnesses.

scribed for obviously if molded into suitable e purpose of a portions of binder material unmixed with the ody material.

2. A molded strainer or screen for wells and the like, comprising a strengthenin skeleton of substantially pure concrete, an a porous filling composed of a granular body pnd a minimum of cementitious binder there- 3. A molded strainer or screen for wells and the like, comprising a strengthenin skeleton of substantially pure concrete, an reinforcing steel, and a porous filling composed bf gravel and a minimum of cement to bind the same together while leaving a large pore-space.

4. A strainer or screen, composed of a bod of gravel from t inch up to inch and a Sui ficient proportion of cement to bind the particles of gravel closely together while leavin a large amount of pore-space between them or filtration, the body and binder being molded to shape.

5. A molded strainer or screen adapted to serve as a lining for Wells and the like, composed of a body of gravel or small stone and sufiicient cementitious binder to hold the particles of the body together and leave between them a large pore-space, and reinforc in ribs molded into the lining.

n testimony whereof, I have signed my name to this specification, in the presence of JOHN R. FREEMAN.

Witnesses:

EDWIN DJPINGREE, JoHN A.

OCoNNnLL. 

